Abstract: In order to achieve a higher coal washing efficiency promote energy conservation and reduction of emissions, and meet the needs of coal users surrounding the mining area, the product structure is defined according to the characteristics of the property of the coal in the mining area. Through analysis on size and density compositions and washability of the coal, it is ascertained that the small coal is up to the required standard in quality indices and there is no need to have it processed, but the coarse coal which is large in quantity and not up to the quality standard has to be cleaned; the coarse coal is easy to wash at the theoretical separation density. Through comparison of the separation results that can be obtained for washing the raw coal from different mines at different lower size limits separation, the heavy-medium vessel is smally selected for use for its better separation performance, lesser generation of secondary slime and higher adaptability. When used for washing down to a 6 mm, a best techno-economical result can be expected.